The Gynecologic Oncology Group was founded on February 20, 1970, as a cooperative group of institutions represented by gynecologists, radiotherapists, medical oncologists and related specialists for conducting clinical trials involving all accepted and experimental treatment methods in a large number of patients with all types of gyneocologic cancer. Currently the Group is composed of 27 participating instiutions with a combined yearly new gynecologic cancer patient load of approximately 2600. There are 15 active study protocols with 675 cases already entered. The number of patients anticipated to be entered into these studies is 1000 per year. Several new study protocols are being considered. A pahtology and a radiotherapy repository have been established to allow for periodic review of histologic slides and radiotherapeutic caluations on all study patients. The reviews will be carried out by pathologist and radiotherapist members of our Group. An endocrinology laboratory has been established to perform assays for gonadotropins, estrogens, and testosterones on patients with rare ovarian tumors.